Respuesta :

Kunchan
(9x - 4) (9x + 4) 
9x (9x + 4 ) -4 (9x + 4)
81x^2 + 36x - 36x - 16
81x^2 - 16

ax2 - b

therefore the value of a is equal to 81

Answer:

value of a is, 81

Step-by-step explanation:

Using the identity rule:

[tex](a+b)(a-b)=a^2-b^2[/tex]

Given the equation:

[tex](9x-4)(9x+4)=ax^2-b[/tex]

Apply the identity rule:

[tex](9x)^2-(4)^2=ax^2-b[/tex]

⇒[tex]81x^2-16=ax^2-b[/tex]

On comparing both sides we have;

[tex]a = 81[/tex] and b = 16

Therefore, the value of a is, 81